Weaker wheats can yield quality breads.
Weaker flour needs less mixing, which has significant advantages. There is less risk of overheating the dough, which can reduce bread quality. Less energy is used in mixing or in cooling over-hot dough, thus saving on costs. Most international work using protein composition and rheology tests to select wheat of high baking quality leads to wheat that needs high work input. The Australians have developed systems using protein composition or dough rheology to identify wheat that has high bread-making quality and moderate work input.
The key to this work is the ascorbic acid improver effect. Large-scale commercial bakeries have for years used ascorbic acid or vitamin C to strengthen dough, a process that mainly occurs during the proofing stage. This makes it possible to produce loaves with good volume and crumb texture. However, Crop & Food Research scientists discovered that strong wheats tend to have a small response to ascorbic acid while some weaker wheats have an excellent response. Some wheat cultivars and genotypes respond strongly to ascorbic acid and some hardly at all. Weaker wheats that respond well to ascorbic acid could produce very good quality bread, as good as strong wheats, while also needing lower work inputs, that is, low mixing requirements.
However, simply adding ascorbic acid to the existing rheological methods does not give a good indication of baking quality, so scientists are working on improved tests and equipment. Protein is, of course, central to dough strength and bread quality and investigators are also trying to establish better protein data as a basis for selecting wheat. This means looking at the composition of protein as well as the quantity present.
In special circumstances, straight protein content can give a prediction of baking quality and bakers still use this measure. In the United States and parts of Europe, most bread wheats tend to be genetically stronger, but in Australasia and Britain there's a more diverse range of genetics in bread wheats. There's a particular protein composition that Australian scientists can select for to get wheat that has moderate work input and high baking quality. This is related to the quantity and size distribution of polymeric glutenin proteins in grain. During proofing of dough, ascorbic acid affects the size distribution of these proteins to produce more of the largest size proteins, and this results in stronger dough.
Further information. Dale Every, Crop & Food Research, Private Bag 4704, Christchurch, New Zealand; phone: + 64 3 325 6400; fax: +64 3 325 2074; email: firstname.lastname@example.org.
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|Publication:||Emerging Food R&D Report|
|Date:||Aug 1, 2006|
|Next Article:||Combination of fibers improves functionality of dough.|